My husband and son dug out a small pond (5 feet by 3 feet, 2 1/2 feet deep) about 4 years ago. We have about four, 7-inch koi and eight 4 inch shabunkins in the pond. Our water quality has been quite clear for the past three years and our fish have been thriving.

We had our pond professionally designed and redone about 10 days ago. The installer removed our fish along with more than enough water from our old pond, to keep them in a holding tank until he was finished completing the new pond. Ater the pond was completed, he put new water in the pond (we have Chicago city water), and then added our fish along with the old water from the holding tank.

Unfortunately, the water has become murkier and murkier; ( we can barely see the fish until they are almost at the surface) it is a golden, light brown color, which I was wondering may have been caused by dust from the new rock materials, but sadder than the fact that we cannot see anything in the pond, one of our beautiful butterfly koi was found floating at the surface the other day. I'm concerned more fish will die.

We have a large filter, a smaller skimmer box and a 2 1/2 foot waterfall that is providing good aeration. What should we do?

Hi Linda,

I'm always dismayed when a relative beginner with a small pond falls victim to a contractor with no actual ponding experience. Unfortunately, what appears to have happened is a combination of what we call "new pond syndrome" and the effects of Chicago tap water on a pre-existing system. I'm hoping that your filtration is the same set-up that you were running your smaller pond with. This will give you half a chance of restoring at least some bioconversion rather quicker than if all of the filters are new.

Your new pond is just that. It's new. Your older pond had an established ecosystem with filter bacteria embedded in the rocks and in the liner as well as in the pipes and filters. It was reasonably well-balanced with your smaller fish. Your move to enlarge the pond was a good one given the robust growth of your for Koi. Your old pond had a volume roughly 280 gallons, which was clearly insufficient for your Koi, given that the appropriate amount of water for Koi runs about 200 gallons per fish for fish less than 8 inches long.

You haven't told me how big your new pond is, but regardless of the size it still has absolutely no biofiltration available. Whatever biological activity was available in the filter died when the system was shut down, unless you used the the filter from the old pond to run your holding tank. If all of your filtration is brand-new, it is basically virgin and barren of life. If this is the case it's going to take 6 to 8 weeks to restore its ability to convert ammonia to non-toxic byproducts. Your new rocks and liner are in a similar state. The best you can supply at this time is frequent water changes, zero feeding, and patience.

The brownish discoloration that you have noticed is a combination of dust from the rocks, dissolved organic materials and probably construction residue from the liner. In the process of refilling your pond, the contractor used Chicago tap water to make up the extra volume. If he did this without pretreating the water he was using to fill your new pond, the chlorine and chloramines in the tap water effectively killed off all of the viable bacteria in the older pond water. If the new pond is significantly larger than the old pond was, there was probably enough new water and therefore enough chlorine to significantly damage the gills on all your fish.

You're going to need a fair amount of patience and an equal amount of energy to save the situation. You will need a sizable quantity of dechlorinator (Stress-X or NovAqua) or an in-line activated charcoal filter (available for about $40 at Wanamaker's) and lots and lots of water changes.

Don't bother buying bacterial boosters. These tend to be relatively worthless from the standpoint of reestablishing nitrifying bacterial populations. You'll need to be water testing at least three times a week, looking for ammonia, nitrite, pH and alkalinity. With the water changes, you will need to be neutralizing chlorine and chloramine present in Chicago tap water. This means that you will also need to check your pond water frequently for these chemicals as well.

The murkiness and particulate matter will filter out or settle out in time. Water changes will help here as well. The brown discoloration caused by the dissolved organics will clear with the water changes and will clear more quickly if you can add a protein extractor to your filter array.

Growing pains are hard. Major changes to what was a balanced ecology always cause casualties of one sort or another. Don't lose faith. Warmer weather is on the way and your pond will recover given patience and a certain amount of effort.

I invite you to read the articles on our website at www.mpks.org. There's a lot of stuff there on new pond syndrome, filtration and spring start up.

In spite of everything, happy ponding,

Bob